1. Field of the Invention
The present invention relates to an electronic stringed instrument capable of detecting vibrations of strings by means of electromagnetic pickups to electrically or electronically create sounds responsive to the detected vibrations, and particularly to an electric guitar or a guitar synthesizer
2. Description of the Related Art
Various kinds of musical instrument have been developed in the past and remarkable progress is now being made relating particularly to electric or electronic stringed instruments.
Electronic stringed instruments which magnetically detect vibrations of strings and create musical sounds responsive to the detected vibrations are disclosed in the following documents.
U.S. Patent Application No. 478,759 filed Feb. 12, 1990 (continuation of U.S. Pat. No. 112,780 filed Oct. 22, 1987, now abandoned); U.S. Pat. No. 184,099 filed Apr. 20, 1988 (now U.S. Pat. No. 4,817,484); and U.S. Pat. No. 256,398 filed Oct. 7, 1988, all of which applications have been assigned to the assignee of the present invention, disclose a guitar synthesizer/electronic guitar using an electromagnetic type pickup device for magnetically detecting vibrations of strings, a pitch extracting device for extracting cycles (or pitches) of the string vibrations from pickup signals generated by the pickup device responsive to the detected vibrations of strings, and a sound-level specifying device for specifying sound levels responsive to pitches extracted by the pitch extracting device.
Further, Japanese Utility Model Disclosure No. 63-51395, the assignee of which is the same as that of the present invention, discloses an electronic stringed instrument using an electromagnetic type pickup device for magnetically detecting vibrations of strings, an envelope detecting device for detecting envelope signals from those pickup signals which are generated by the pickup device responsive to the vibrations of detected strings, and a peak measuring device for measuring peaks of the envelope signals detected by the envelope detecting device. The peak of envelope signal represents the strength of force by which the string is flipped, and it is used to control the volume of musical sounds created by a sound source in response to the vibration of strings.
Furthermore, U.S. Pat. No. 4,723,468 discloses an electronic guitar/guitar synthesizer using an electromagnetic type pickup device for detecting vibrations of strings, and a fret-position detecting device for detecting a string-pressing position on a finger board by using ultrasonic signal generated by the pickup device represents the state of the vibrating string, and it is used to specify start and finish of musical sounds created by a sound source in response to the vibration of strings and to control the volume of the musical sounds.
Still further, U.S. Pat. Nos. 4,372,187, 4,760,767 and 4,630,520 disclose an electronic guitar using an electromagnetic type pickup device for magnetically detecting vibrations of strings to output pickup signals responsive to the vibrations of detected strings, and a fret-position detecting device for electrically detecting contact positions of a pressed conductive string at which the pressed string contacts a plurality of frets on a finger board. A pickup signal generated by the pickup device represents the state of the vibrating string, and it is used to specify start and finish of musical sounds created by a sound source in response to the vibration of strings and to control the volume of the musical sounds.
Still further, U.S. Pat. No. 4,765,219 discloses an electronic violin using a pickup device for magnetically detecting vibrations of strings to generate pickup signals responsive to the vibrations of detected strings.
In the case of the above-mentioned electronic stringed instruments, material of strings must have magnetism to enable the electromagnetic type pickup device to detect vibrations of strings as electric signals, and steel, for example, is used as the material of strings. In the case of these stringed instrument, therefore, non-magnetic strings, such as silk, nylon, gut or the like, used in acoustic guitars and being capable of creating unique tone colors cannot be used.
Japanese Utility Model Disclosure No. 61-38697 discloses a proposal to solve the above described problem. In this proposal, a magnetic paint made by mixing a magnetic powder such as iron oxide powder or mixture of the magnetic powder with a painting agent such as synthetic resin paint, is painted on a part of the nonmagnetic string. This proposal, however, does not make it possible to use those non-magnetic strings, which are not coated with the magnetic paint but which are commonly on the market, when any of the strings coated with the magnetic paint is broken. This makes it necessary for players to carry the strings coated with the magnetic paint as spares. When the special strings are not be carried, it will take much time to get a string coated with the magnetic paint. In addition, since the magnetic paint is only partially applied to the string, the string must be stretched on the body unit of the instrument in such a way that its magnetic-paint-coated area is opposed to the corresponding pickup, thereby making the strings stretching operation troublesome. Further, the magnetic paint is likely to peel off.